Cation exchange materials and their preparation



CATION EXCHANGE MATERIALS AND THEIR PREPARATION Mayer B. Goren, Oklahoma City, Okla, assignor to Kerr- McGee Oil Industries, Inc., a corporation of Delaware No Drawing. Application March 16, 1953, Serial No. 342,72?

20 Claims. (Cl. 196-22) This invention relates to carbonaceous cation exchange materials having improved properties and to the preparation of such materials. More particularly, this invention is concerned with the preparation of carbonaceous cation exchange materials that have high exchange capacities in both the hydrogen and alkali metal cycles.

The characteristics that are desirable in a satisfactory cation exchange material which is to be used for softening or deionizing water containing dissolved contaminants may be summarized as follows:

1. High exchange capacity per unit volume or weight of the material.

2. Physical stability; i. e., resistance toward attrition and fining during use. The particles should be mechanically fairly hard and have good resistance toward crushing as determined empirically by a feel test or more accurately through controlled attrition tests in a suitable apparatus such as a ball mill.

3. Freedom from color throw-off; i. e., the material should be relatively insoluble and show a minimum tendency to dissolve in water with which it is in contact.

4. It should not show an excessive adsorptive capacity for the regenerant; i. e., washing out of the excess of acid or salt used in regenerating the cation exchange material should be quickly and easily achieved so that large quantities of wash water are not needed.

The preparation of carbonaceous cation exchange materials has been described in a number of patents and publications. These materials are generally prepared by treatment of a carbonaceous material such as bituminous coal, peat, lignite, etc., with a sulfonating agent such as concentrated sulfuric acid, oleum or gaseous sulfur trioxide to effect sulfonation and thereby introduce on a relatively insoluble lattice, reactive groups that are capable of undergoing exchange reactions with cations in the solution. Such sulfonated products possess the aboveenumerated desirable properties to varying degrees and many have proved highly satisfactory for softening or deionizing water.

By the term asphalt-type bituminous materials as used hereinafter in the specification and claims is meant semi-solid to solid pyrogenous and naturally occurring asphalts (bitumens and pyrobitumens), one or more semisolid to solid fractions or components thereof, or semisolid to solid products obtained by blowing these materials or one or more of their components or fractions with air or an oxygen containing gas in the presence or absence of catalysts. Examples of such materials include gilsonite, grahamite, wurtzilite, albertite, elaterite, native asphalts, such as Trinidad asphalt, etc. Blown asphalt- -type bituminous materials include those blown with air or an oxygen containing gas either in the presence or absence of catalysts such as phosphorous pentoxide, ferric chloride, cobaltic salts, etc. By the term components or fractions of pyrogenous and naturally occurring asphalts is meant asphaltenes, resin and oil mixtures, and separate resin and oil fractions. These may be obtained.

States Patent for example, by the method as described in copendingi application Serial No. 218,480, filed March 30, 1951.

These asphalt-type bituminous materials possess solubility, hardness, and reaction characteristics which make them desirable as starting materials for the preparation of cation exchange materials. A further advantage to be offered in the processing of such asphalt-type biturninous materials as compared with the processing of coals or related bituminous substances is that the former are fusible and no loss of fines occurs in the grinding of the material prior to sulfonation since the fines can be melted, cast and reground. This would be reflected therefore in a lower cost of production and therefore a lower cost for the product.

The sulfonation of asphaltenes for the production of ion exchange materials has been mentioned in French Patent 831,917 of 1938. This patent does not give a specific example of the sulfonation of asphaltenes although it does illustrate the sulfonation of a petroleum pitch (M. P. 110 C.) with sulfuric acid in the presence of sodium dichromate. This product is said to have a capacity of 46 grains calcium ion per kilogram. Upon applying this method of sulfonation to asphaltenes, it has been found that the resultant product exhibits an exchange capacity of ten grams of calcium ion per kilogram of product. Twelve grams of the sample on regen eration with 50 milliliters (ml.) of 0.4 N-hydrochloric acid deionizes 750 ml. of hard water containing 400. p. p. m. hardness calculated as calcium carbonate. From this, it is apparent that although mention is made: by this French patent of asphaltene sulfonation for pro-- ducing cation exchange materials, the sulfonated asphalt enes resulting from the only sulfonation method taught by this patent are unsatisfactory. A clue to the reason for the misleading statements made in this patent relative to sulfonated asphaltenes is apparent upon considering the prohibitive wash requirement of the product. Thus, the product after washing to neutrality, conversion to the sodium cycle by treatment with sodium chloride, and regeneration with an appropriate quantity of acid, required washing with 870 ml. of distilled water before the efliuent was neutral to Congo red indicator. Therefore, if the product is not washed completely, it would appear to be of very high capacity. Furthermore, the product shows a considerable amount of color throw-off in both the acid and sodium cycle, presumably owing to oxidative degradations incurred in the sulfonation reaction.

U. S. Patent 2,382,334 describes a process for the preparation of cation exchange materials by sulfonating wood, lignite, peat, bituminous coal and similar materials with a concentrated liquid sulfonating agent, thereafter washing and drying this product and resulfonating with sulfur trioxide gas. This treatment is said to produce a product of high exchange capacity without adversely affecting the hardness or color-throwing characteristics of the material.

When the sulfonation method of U. S. Patent 2,382,334 is applied to asphalt-type bituminous materials such as asphaltenes, gilsonite, blown asphalt and other related bituminous materials, the exchange capacity of the sulfonated product is always slightly higher than that of the once-sulfonated material but the washing characteristics are very poor, the product is extremely friable and color throw-off is very pronounced.

Accordingly, it is a principal object of the present invention to provide a sulfonated asphalt-type bituminous material of high exchange capacity, good physical stability, excellent washing characteristics, and improved color throw-off characteristics.

It is a further object of the present invention to provide a sulfonated asphalt-type bituminous material ofi 3 the" aforesaid type'possessingthese properties in the hydrogen-andalkali metal cycles.-

These and other objects will become more apparent from the following description of the present invention.

I have discovered that the reaction product'cfau asphalt-type bituminous material with concentrate-Chsulfuric acid-further reacted with oleum provides a highly satisfactory carbonaceous cation exchange' material:

Such doubly sulfonated products are of exceptionally high exchange capacity; possess" good physical stability; have excellent washing characteristics, and possess exceptionally low color throw-off characteristics".

In accordance with the process ofthe present invention; an asphalt-type bituminous material is first sulfo hated-with concentrated sulfuric acid; in order to obtain a'high degree ofsulfonation; to providea'highsurface area for contacting the aqueous solution to be treated with the final product and to provide a'product which may be easily handled, the particle size ofthe asphalt-type bituminous material should be between approximately and '50 mesh. This'range of particle size is easily obtained by heating the'material to a molten condition, allowing the same to solidify asa solid massand thengrinding and screening the material to'the desired mesh size. Fines obtained as the result of this screening operation may be remelted, solidified and reground.

Aboutl' to 8 parts by weight of concentrated sulfuric acid for each part by weight of asphalt-type bituminous material sulfonated has proved satisfactory for the ini-- tial sulfonation step of the present invention although smaller ratios may be employed. The temperature of sulfonation is preferably maintained between 70 and 150 C. The time required for this sulfonation is usually in the neighborhood of several hours although. shorter times may'b'e used.

After initial sulfonation with concentrated sulfuric acid, the product may be washed and dried prior to sub sequent'sulfonation with oleum. Instead, residual acid, if any, may be drained off and the product sulfonated with oleum without the benefit ofan intermediatewashing and drying" step. The latter procedure ispreferred in that the resultant product is handled less by eliminating:the washing and'drying'step' and thus,- the once-sulfonated material is broken up less.

sulfuric acid andi oleumsulfonation steps is to reduce the amount ofv oleum necessary to obtain'a given degree ofvactivity. Consequently, itwould. be'unnec'essary to drain oif residual acid ifa larger quantity of oleum is used in the final sulfonation step.

Satisfactory products may be obtained byoleum sulfonation of the once-sulfonated material when approxi mately 2 to 10 parts by weightv of oleum'aare'used foreachpart by-weight'of-once-sulfonated asphalt type bi-- tuminous material treated. The per cent of free. $03

in the oleum employed is not critical although preferred.

results are obtained for example when using; a'20% oleumin place of a 10% oleum. The te'mperatureof the olcum sulfonation preferably is maintained: within the range of 70 through 150 C. Generally, oleumsulfonation of the once-sulfonated asphalt-type-bituminous material may be carried out infrom l to" 3 hoursalthough satisfactory products maybe obtained in a shorter The purpose" ofdraining off any. residualacid between the concentrated ried out with water below its boiling point or with steam or superheated water.

The above-described washing operation in the alkali metal cycle, i. e., sodium, potassium or lithium cycle, with hot water has the particular advantage of removing a small amount of soluble material in the doubly sulfonated asphalt-type bituminous material and thereby improves its color throw-o5 characteristic-s; Consequently, where exceptionally high freedom from color throw-01f is particularly desirable, this latter method of conversion to the alkali metal cycle and washing'with hot water at a temperature below 150 C. is'preferred. However, even though this preferred washing technique is not employed, the product obtained by removing excess acid and repeated washing with water Without the conversion to alkali metal. cycle is greatly improved in its color throw-off characteristics as compared with an asphaltic material resulfonated with sulfur trioxide.

The following examples are for the purpose of illustrating the present invention but are not limiting to thescope thereof which is set forth in the appendedclaimsz Example I A vacuum-reduced asphalt of 89' penetration! and a ring and'ballsofteningpoint of 120 F. was treated with 10 volumes of pentane, andthe precipitated asphaltenes were filtered, dried, brought to fusion by heating, and allowed to solidify as a solid mass. This product was then ground and screened to obtain a 20 to 40 mesh ma terial; Fines were rernelted, solidified and reground.

109 parts by weight of the 20 to 40 mesh asphaltenes were treated with 540 parts by weight of 66 'B. sulfuric acid ina vessel suitably equipped with'an agitating means and vented for the escape of gases formed during the reaction. Heat was applied slowly to the reaction mass to bring it to a temperature of approximately 100 C. which was maintained for two hours; After. cooling, the product was drained of excess acid and then carefully washed free of acid. The product of this reaction was a shiny, hard, granular material resistantto attrition.

l2 grams-of this product was-placed in avgla'ss column,

exhausted by treatment with an aqueous sodium'hydrox-" ide solution, thoroughly washed'and regenerated with dilute hydrochloric acid. Hard water containing 400 p. p. m. hardness, calculated as CaCOs, was then passed through the column until the acidity of the efliuent indicated a leakage of 20 p. p. mLof hardness through the column. The column was then washed, regenerated as described above, and treated with'hardwater again. This proce'sswa'srepeated a number of times to obtain a constant'value of exchange capacity. In all instances, ap=

proximately'l liter of water was required to wash out the regeneratingacid and on an average the material in the'column deionized about 550 m1; of the hardwater prior to leakage reaching the'limit defined above. Thus, the product had an average exchange capacity 'of' about 0.36 milliequivalent per'gram (meq./g.).

Example II The product of Example I was further activated by treating lSp'arts by weight of the dry material with parts byweight'of 20% oleum. The temperature was controlled by cooling and slow addition of the reagent.

After'the initial reaction had spent itself, the mixturewas heated and maintained for two hours at or'just below" C.- The product was then washed, finally in the sodiurn: cyclewith hot water and steam-and then dried. A 12 gramsample tested in the same manner as described in Example 1' above required somewhatless: than aft tape? Example 111 Example IV The once-sulfonated product as obtained in Example I, after washing and drying, was resulfonated by retreating 100 grams of this material with 360 ml. of 95% sulfuric acid at 150 C. for two hours. After cooling, the excess liquid was filtered off to recover 175 ml. of acid of density of 1.65 and the residue was thoroughly washed to remove all acid. In column operation, the materials showed improved washing characteristics (230 ml. of wash water was being required on a regenerated 12 gram sample) but the exchange capacity had improved over the exchange capacity of Example I by only approximately Example V A sample of gilsonite having a pressed powder ring and ball softening point of 325-330" F. was crushed and sieved to a mesh size of between 10 and 20. 100 grams of this material was sulfonated by treatment with 540 grams of 95% sulfuric acid at 100 C. for two hours and the product was then thoroughly washed and dried. In column operation as described in the previous examples, the sulfonated gilsonite exhibited very poor exchange characteristics, a very slow rate of flow being required to effect exchange and the volume of hard water deionized was 750 ml. This indicates a working capacity of approximately 0.46 meq./ g. Furthermore, the material adsorbed the excess regenerant to such an extent that excessive volumes of water were needed to wash it free of acid.

Example VI 20 parts by weight of the washed and dried sulfonated product of Example V was treated with 115 parts by weight of 20% oleum and maintained at a temperature below 5 C. for one and one-quarter hours. The mixture was then allowed to warm up on its own and when the initial reaction moderated, the mixture was heated on a water bath for two hours to complete the reaction. The product was then thoroughly washed and dried. In column operation as carried out in previous examples, 10 grams of the material was Washed free of excess regenerant with approximately 200 ml. of water and the regenerated product deionized 1700 ml. of the standard hard water. This indicates a working capacity of approximately 1.36 meq./ g.

Example VII A vacuum-reduced asphalt of 87 penetration and 117 F. ring and ball softening point was oxidized by blowing with a current of air for hours at 500 F. The product of this oxidation had a softening point of 271 F. (ring and ball), penetration of 6 and a penetration index of +5. This blown asphalt was chilled, crushed and screened, and the 10 to 30 mesh material was retained while the fines were remelted, cast and reground. 100 grams of the sized material was contacted with 300 m1. of 95% sulfuric acid, allowed to stand overnight and then heated to 100-110 C. and maintained for two hours. After cooling, the excess acid was recovered by filtration and the residue of sulfonated product was washed completely free of acid. Evaluation for ion exchange characteristics in column operation showed that 12 grams of the material after regeneration from a sodium cycle with dilute hydrochloric acid required over a liter of wash water for re- 6 moval of excess regenerant and deionized 800 ml. of the standard hard water.

Example VIII 25 grams of the washed and dried product of Example VII screened to 20 to 40 mesh was suspended in 38 ml. of sulfuric acid and allowed to stand for 16 hours. An additional 20 cc. of 95% sulfuric acid was added followed by the careful addition of 58 ml. of 20% oleum. The mixture was allowed to reach its own equilibrium temperature before it was heated to water bath temperature for two hours. After cooling, the product was thoroughly washed, finally in the sodium cycle with hot Example IX The pentane soluble fraction of Example I comprising a mixture of oils and resins was separated from the pentane by distillation and was air-oxidized by blowing in the presence of 0.75% phosphorus pentoxide to obtain a product having a softening point of 314 F., a penetration of 5 and a penetration index of +6. This blown resin-oil mixture was sulfonated in the same manner with the same proportions of sulfonating agents as was the blown vacuum-reduced asphalt of Example VII. In column operation as carried out in previous examples, a 12 gram sample after regeneration from a sodium cycle with dilute hydrochloric acid required approximately one liter of wash water to free it of excess regenerant and deionized 800 ml. of the standard hard water prior to leakage of 20 p. p. in. through the column. This material possessed a working capacity of approximately 0.53 meq./g.

. Example X The product of Example IX was sulfonated in the same manner and with the same agents in the same proportions as was done to the product of Example VII in Example VIII. A 12 gram sample of the resultant product required about ml. of wash water to free it of excess regenerant and deionized approximately 1800 ml. of the standard hard water prior to leakage of 20 p. p. m. through the column. Thus, the working capacity of this material was approximately 1.2 meq./g.

Example X] A vacuum-reduced asphalt having a softening point of 113 F. and penetration 92 was treated with 10 volumes of liquid propane at ambient temperature in a rotating pressure vessel for two hours to attain equilibrium. After this, the propane-insoluble heavy phase was collected and freed of propane. This product had a ring and ball softening point of F. To increase its hardness, it was air-blown at 530 F. for 19 hours. As a result, a product having a ring and ball softening point of 303 F. and penetration of 2 was obtained. This product was chilled, ground and screened to a mesh size of between 20 and 40 and sulfonated in the manner described in Examples VII and VIII above. After regeneration from a sodium cycle with dilute hydrochloric acid, 12 grams of the washed and dried doubly sulfonated material deion: ized 1550 ml. of the standard hard water as compared with 700 ml. deionized by the once-sulfonated material.

Example XII Pentane insoluble asphaltenes as prepared in Example I were melted, cast, ground and screened to a mesh size of. between and,40. partsof the. thusly, screened material was treated with 130 parts'of'95%' sulfiiric, acid and heated at water bath temperature for one and one-half hours with stirring. The mass was then allowed to coo1'and:145 -parts.-of 20% oleum was added, stirred-in, and the mixture.was.heated--an. additional one. and onehalf-hoursto-completethesulfonation; The product was cooled, washed thoroughly to remove excess acid, con-- verted to the sodium cycle andtwashed with hot water and steam :to remove a-small amount of soluble material and dried. The exchange capacity wasdetermincd on a 12 gramsample regenerated from the sodium cycle with dilutehydrochloric acid. In column operation, it dcionized- 1250 ml. of standard hard water before the effluent showeda' leakage of 20 p.- p. m. hardness. The product in thecolumnwas easily washed free of excess regenerant, slightly over; 100. ml; of wash water being required. Thus, the-product hadaworking capacity of approximately. 0.84 meq/g.

I claim:

1. A process of'preparingia carbonaceous cation exchange material which comprisessulfonating an asphalttype bituminous material with concentrated sulfuric acid, further sulfonating each part by Weight of the resultant product with from 2 to 10 parts by weight of oleum and washingnexcess' acidlout of the resultant product.

2. A process of preparing a carbonaceous cation exchange material which comprises sulfonating an asphalt? type bituminous material with concentrated sulfuric acid, further sulfonating:eachlzpart. byweight oflthe re.- sultant product with. from 2- to 10. parts by. weight of oleum, the temperatures of both sulfonation steps being:- maintained within the range.of.70 through 150 C., and washing excess acidiout of the resultant product;

3. A process of' preparinga carbonaceous cationxexchange material which comprises sulfonating an asphalt type bituminous material with concentrated. sulfuric acid, further sulfonating. each part by weight: of the resultant product'with from.2.=to 10. parts by weight'of oleum, washing excess acid -out'of the resultant product, converting the washed product to an alkali metal cycle; and washing with water at a' temperature below 150 C.

4. A process. of preparing'acarbonaceous cation exchange material which comprises sulfonatingan asphalttype bituminous material'with concentratedsulfuric acid, further sulfonating each part by weight of the resultant product with from 2 to 10 parts by weight of'oleum, the temperatures of both sulfonation steps-being maintained within the range of 70 through 150 C., washing excess acid out of the resultant. product, converting. the washed product to an alkali. metal cycle, and washing, with water at a temperature below 150 C.

5. A process of preparing a carbonaceous cation exchange material whichcomprisessulfonating asphaltenes 7 with concentrated sulfuricacid, further sulfonating; each part by weight of the resultantproduct.With-frQmaZ to10 parts'by weight of oleumand washing excessaoid outof the resultant product.

6. A process of preparing a carbonaceous-cationexchange material which comprises sulfonating: asphaltenes with'concentrated sulfuric acid, further sulfonating each part by weight of theresultantproduct with from= 2' to 10 parts by weight of oleum, the temperatures of both: sulfonation steps being maintained withinthe range of 70 through 150* C., and washing excess acidout of; the: resultant product.

7. A process of preparinga carbonaceous cation exchange material which comprises sulfonating: asphaltenes with concentratedsulfuric acid,.further sulfonatingzeach part by weight of theresultant product with from 2 to-lO parts by weight of oleum, washing excess acid out of the resultant product, converting the washed product to an alkali metal cycle and washing with water at aternperature below 150 C.

lo' partsbyv weight: of: oleum; the temperatures. of; bothsulfonationrsteps being maintained'withinthe; range-of. througlrl50 C., washing excess acid out of the product thusaobtained, converting the washedproduct to analkali metal. cycle: andiwashing with. water atav temperature below f C.

9. A process of preparing a. carbonaceous cation exchange material which comprises sulfonating blown asphalt-type bituminous material with concentrated sulfuric acid; further sulfonating each part by weight of the resultanflprod'ucbwith from 2 to- 10 parts by weight of oleum'and washing excess acid out of the resultant prodnet.

10; A process of=preparinga carbonaceous cation exchange material'which: comprises sulfonating blown as phalt-type bituminous=material with concentrated sulfuric acid; further sulfonating each part by weight of the re sultant product with frorn 2 to 10 partsby weight of oleum, the temperatures ofboth sulfonation steps being maintained' within-the range of 70 through 150 C., and washing excess acid outoftheresultant product.

11. Aprocess of preparing a carbonaceous cation exchange materialwhich'comprises sulfonating'blown asphalt-typefbituminous material with concentrated sulfuric acid; further sulfonating each'part by weight of the re.-

sultant' product with.v from'2' to 10 parts by weight of oleum, washing excess acidout of the resultant product, converting the'washed: product to an alkali metal cycle and washing with' water at a'temperature below 150 C.

12? A process of preparing a carbonaceouscation exchange materialwhicli comprises sulfonating a blown asphalt-type bituminousjmaterial with concentrated sulfuric acid, further. sulfonating each part'by weight of the re sultant productwith' from 2 to 10 parts by weight of oleum, the temperatures of both sulfonation steps being maintained within the range of 70 through 150 C., washing excess acid outof the resultant product, converting the washed product to an alkali metal cycle and washingwith-water. at a temperature below 150 C.

13. A process. of. preparing a carbonaceous cation exchange. material which comprises sulfonating a blown product. of an. asphaltene-free asphalt-type bituminous materialwith a concentrated sulfuric acid, further sulfonating each .partby weight of the resultant product with from 2.to.10, par-tsby. weight of oleum and washing excess acid out of. the resultant product.

14. Aprocessof. preparing a carbonaceous cation exchange material which comprises. sulfonating a blown product ofanasphaltene-free asphaltatypebituminous material with.concentrated sulfuric acid, further sulfonating each part-by. weight: of the resultant product with. from 2 to 10 parts by weight of oleum, the temperature-of both sulfonation steps being maintained within the range of 70 through 150 C., andwashing. excess acid out of the resultant product.

15'. A process. of preparing a carbonaceous cation exchange material which comprises sulfonating' a blown productlof an1aspha1tene-freeasphalt-type bituminous material with concentrated sulfuric acid, further sulfonating each part by weight of the resultant product with from 2 to IO'parts by weight ofoleum, washing excess acidout' ofj the'resultant product, converting the washed productto an alkalimetal cycle, and washing with water at a temperature below 150 C.

16; A process of preparing a carbonaceous cation exchange, material which comprises sulfonating a blown product of an asphaltene-free asphalt-type bituminous material with concentrated sulfuric acid, further sulfonating. each part: by weight of the resultant: product with from 2 to. 10 partsby Weight of oleum, the temperature of both sulfonation steps being, maintained within the range of 70 through 150 C., washing excess acid out of the resultant product, converting the washed product to an alkali metal cycle, and washing with water at a temperature below 150 C.

17. A carbonaceous cation exchange material comprising each part by Weight of the reaction product of an asphalt-type bituminous material with concentrated sulfuric acid further reacted with from 2 to 10 parts by weight of oleum and washed free of excess acid.

18. A carbonaceous cation exchange material comprising each part by weight of the reaction product of a blown asphalt-type bituminous material with concentrated sulfuric acid further reacted with from 2 to 10 parts by weight of oleum and Washed free of excess acid.

19. A carbonaceous cation exchange material corn prising each part by weight of the reaction product of a blown asphaltene-free asphalt-type bituminous material with concentrated sulfuric acid further reacted with from 10 2 to 10 parts by weight of oleum and washed free of excess acid.

20. A carbonaceous cation exchange material comprising each part by weight of the reaction product of asphaltenes with concentrated sulfuric acid further reacted with from 2 to 10 parts by Weight of oleum and washed free of excess acid.

References Cited in the file of this patent UNITED STATES PATENTS 1,459,328 Forrest et al. June 19, 1923 1,578,235 Forrest et al. Mar. 23, 1926 1,868,211 Nobel July 19, 1932 2,208,171 Urbain July 16, 1940 2,299,469 DAntal Oct. 20, 1942 2,3 82,334 Riley et al Aug. 14, 1945 

1. A PROCESS OF PREPARING A CARBONACEOUS CATION EXCHANGE MATERIAL WHICH COMPRISES SULFONATING AN ASPHALTTYPE BITUMINOUS MATERIAL WITH CONCENTRATED SULFURIC ACID, FURTHER SULFONATING EACH PART BY WEIGHT OF THE RESULTANT PRODUCT WITH FROM 2 TO 10 PARTS BY WEIGHT OF OLEUM AND WASHING EXCESS ACID OUT OF THE RESULTANT PRODUCT.
 17. A CARBONACEOUS CATION EXCHANGE MATERIAL COMPRISING EACH PART BY WEIGHT OF THE REACTION PRODUCT OF AN ASPHALT-TYPE BITUMINOUS MATERIAL WITH CONCENTRATED SULFURIC ACID FURTHER REACTED WITH FROM 2 TO 10 PARTS BY WEIGHT OF OLEUM AND WASHED FREE OF EXCESS ACID. 